There is a general desire to describe and/or control various means of human locomotion. Such description and/or control can assist with navigation, predicting arrival times and the like. For example, the description of the speed of an automobile (e,g. provided by a speedometer) may be used to predict how far the automobile can travel in a particular length of time and/or when the automobile will arrive at a particular destination. Speed control of the automobile (e.g. provided by a cruise control system) can be used to achieve target arrival times, target speeds and the like.
There is a similar desire to describe and/or control human locomotion (e.g. locomotion, such as running, walking and/or the like).
Like the case of the exemplary automobile discussed above, such control can assist with achieving target navigation parameters, such as arrival times and the like. By way of non-limiting example, description and control of human locomotion can also have application to training (e.g. for athletes, recreational runners, soldiers and the like). Many runners, ranging from world class athletes to recreational runners, set objectives (goals) to cover a given distance in a certain amount of time. To achieve such objectives, such runners have to run the distance at a particular speed or with a particular speed profile.
Various systems and techniques are known in the prior art to estimate running/walking speed and/or position. Such prior art systems include:                The “Nike+”™ sportsband developed by Nike, Inc and the “Rock and Run”™ system developed by Apple Inc. in conjunction with Nike, Inc. use an in-shoe sensor and a handheld or band-mounted user interface to estimate time, distance and speed and to provide such information to the shoe wearer—(see http://nikerunning.nike.com/nikeos/p/nikeplus/en_EMEA/sportband and http://www.apple.com/ipod/nike/run.html).        The “Forerunner”™ series of wrist-worn devices sold by Garmin Ltd. which use global positioning system (GPS) technology to estimate position, speed and time and to provide such information to the user—(See https://buy.garmin.com/shop/shop.do?cID=141&fKeys=FILTER_SERIES_FORE RUNNER).        The “Polar S3 Stride Sensor W.I.N.D.”™ sensor sold by Polar Electro Oy which mounts to the user's shoe, measures the acceleration of a user's foot and uses this acceleration information to estimate ground speed and/or distance—(http://www.polarusa.com/us-en/products/accessories/s3_Stride_Sensor_WIND).        The “Speedmax”™ technology developed by Dynastream Innovations Inc. which uses inertial sensors to detect running/walking speed and distance.        
Other than for providing the user with information about their speed, however, these systems and techniques do not appear to permit automatic control of human running/walking speed and/or position. Using such systems, a user would have to repetitively monitor the user interface (or repetitively receive output from an output device (e.g headphones)) and then the user would have to determine on their own whether they were meeting their speed objective. Based on their own consideration of whether they were meeting their speed objective, the user would then have to adjust their speed on their own and then recheck the user interface at a later time to determine if their new speed meets the speed objective. For most humans, this speed adjustment is difficult to perform accurately. No information is provided to the user between the time that the user first checks the user interface and the time that the user subsequently rechecks the user interface at the later time. These systems are analogous to the speedometer of an automobile, wherein speed information is provided to the driver, but the driver adjusts the speed on their own (i.e. without automatic cruise control). Such systems do not provide automatic speed control of locomotion in a manner that is analogous to cruise control in an automobile.
There is a desire for systems which help a subject to automatically control a speed and/or position of their human locomotion (e.g. locomotion such as running and/or walking).
In addition to or in the alternative to controlling locomotive speed and/or position, there is a general desire to control locomotion intensity. Locomotive intensity is usually estimated based on one or more measurable or estimatable or measurable intensity indicators. Such intensity indicators include, by way of non-limiting example, hear rate, metabolic rate, oxygen consumption, perceived exertion, mechanical power and/or the like.
Various systems and techniques are known for estimating hear rate. Such systems include:                Strapped heart rate monitors (for example by Polar Electro Oy—see http://www.polarusa.com/us-en/products/get_active); and        Strapless heart rate monitors (for example by Physi-Cal Enterprises Inc.—see http://mioglobal.com/main_products).Again, as is the case with speed measurement, these heart rate monitors merely provide the user with information about their heart rate and do not appear to permit automatic control of the intensity of human locomotion. Accordingly, these systems suffer from analogous drawbacks to those of the speed and distance measurement systems described above.        
There has been some attempt in the art at control of a user's heart rate. Examples may include the BODIBEAT™ music player marketed by Yamaha—see http://www.yamaha.com/bodibeat/consumer.asp; and the TRIPLEBEAT™ application marketed by the individual Dr. Nuria Oliver—see http://www.nuriaoliver.com/TripleBeat/TripleBeat.htm.